The present invention relates to an image processing apparatus and an image processing method for proofing the reproduced color of a reproduced image.
According to prior art practice, when an original image for a display (a first output apparatus) for outputting a color image is to be outputted by means of a color printer (a second output apparatus), the output colors are different between the display and printer; consequently, a reproduction profile showing the relationship of output colors between the display and printer is used to convert the original image signal for display into the reproduction image signal for printer (e.g. Patent Documents 1 and 2).
In this case, in order to avoid wasting a recording medium due to printer outputting, it is preferred to check in advance to see whether or not the output color changes according to the type of the device. For this purpose, before starting printing operation, a color image for proofing, having the color maximally similar to that of the image to be printed by the printer—namely, a proof image—is outputted through a poof device such as a color display or other color printer.
Incidentally, in recent years, there has been a remarkable improvement in the color printer performance. An image can be outputted in hifi colors such as R, G and B, in addition to the normal colors of Y, M, C and K.
Accordingly, to get the proof image as described above, the following methods have been proposed; a method for getting a proof image for printer, using a normal ink (coloring material) and one type of hifi color ink (Patent Documents 3 and 4), and a method for getting a proof image for printer, for measuring all colors in a combinations of the types of inks used and adjusting colors based on this measurement (Non-patent Document 1).
The following describes the method disclosed in the Non-patent Document 1. According to this method, an arithmetic processing apparatus 101 creates a profile for reproduction 100, for converting an original image signal into the image signal for reproduction, as shown in FIG. 7. This profile for reproduction 100 shows the relationship between the output colors of a display 102 and a printer 103. It is created as a Look Up Table (LUT).
Then an arithmetic processing apparatus 105 creates a profile for proof 104 for converting the image signal for reproduction into the image signal for proof. The profile for proof 104 indicates the relationship between the output colors of the printer 103 and proof apparatus 106. The profile for reproduction 100 and profile for proof 104 can be created as one profile.
Then the arithmetic processing apparatuses 101 and 105 perform interpolation arithmetic processing, and convert the original image signal into an image signal for proof, based on the profile for reproduction 100 and profile for proof 104.
Based on this image signal for proof, the proof device 106 outputs a proof image.                [Patent Document 1] Official Gazette of Japanese Patent Tokkaihei 11-069176        [Patent Document 2] Official Gazette of Japanese Patent Tokkai 2001-136401        [Patent Document 3] Official Gazette of Japanese Patent Tokkai 2001-157074        [Patent Document 4] Official Gazette of Japanese Patent Tokkai 2000-62253        [Non-Patent Document 1] Adobe system, “Soft Proofs of Adobe Photoshop”,[online], Adobe systems, [Searched on Oct. 13, 2003], Internet <URL http: //www.ilcolor.co.jp/images/knowledge/trn/pdf/PS#SettingPrint#J.pdf>        
However, according to the methods disclosed in the aforementioned Patent Documents 3 and 4, when the printer mixes the hifi color to use it for color reproduction, the image signal for proof cannot be obtained.
Further, in the method disclosed in the aforementioned [Non-Patent Document 1], when creating a profile for proof 104, there is an exponential growth in the combination between the output colors of the printer 103 and proof apparatus 106, with the increase in the number of the color materials m used by the printer 103. This raises the problem of requiring a vast amount of memory capacity for arithmetic processing. For example, when each color is divided into five grades to create a color card, the number of combinations, there is an exponential increase of 54=625, 55=3125, 56=15625, 57=78125, . . . for m=4, 5, 6, 7, . . .